In general, children are helped by others to support their balance or auxiliary wheels are installed on both sides of a rear wheel to achieve the learning purpose when the children learn how to ride a vehicle. However, such arrangement can only achieve the effects of stabilizing a vehicle body and preventing the children from falling down from the vehicle, but it has not much practical help on the effect of learning how to ride a vehicle sooner. On the contrary, children may even become psychologically dependent over time and fail to develop the potential of maintaining their balance.
Therefore, a recreational vehicle (also known as a slider or walker) without any pedals or chain is introduced into the market. Basically, the recreational vehicle comprises a front fork installed at the front of a frame for connecting a handlebar and a front wheel, a rear wheel installed at the other end of the frame, a seat installed at the middle section of the frame and provided for a rider to sit thereon, so that the rider can hold the handlebar by both hands and stomp at the ground by both legs to push the front wheel and rear wheel to rotate in order to drive the recreational vehicle forward and train the children's muscle strength and balance.
In a conventional recreational vehicle, both front and rear wheels are single wheels, so that the wheels can slide by touching the tire tread of each wheel on the ground. To provide flexible control and operability, the width of the tire tread of each wheel is substantially equal to the width of the tire of a general children's vehicle, and the tire tread of the wheel is not adjustable, so that the level of difficulty of the learning is still very high. As to a younger child, the learning and practice are relatively more difficult and dangerous, and such recreational vehicle reduces the adaptability and practicality significantly.